Mine-prop.



E. SGHAFER.

MINE PROP.

APPLIGATION FILED JUNE 24, 1909.

Patented Jan. 18, 1910.

I F i "FFIE.

EMANUEL SCHAFER, F DUSSELIDORF, GERMANY.

MINE-PROP.

Application filed June 24,

Specification of Letters Patent.

Patented J an. 18, 1910.

1909. Serial No. 503,989.

To all whom it mag concern:

Be it known that I, EMANUEL Sol-mink, a

subect of the German Em oeror residing at l a u j of ring-sections 0, between pipe (Z, and neck Dusseldorf, Germany, have invented new and Improved Mine-Prop, of which the following is a specification.

This invention relates to a mine prop com posed of telescoped pipe sections which are so connected by a concealed friction joint that any increase of pressure 011 the prop will correspondingly increase the resistance of the joint.

in the accompanying drawing: Figure 1 is a side elevation, partly in section, of my improved. mine prop; Fig. 2 a cross section on line r\ B, Fig. 1; Fig. 3 a cross section on line CD, Fig. 1, and Fig. 4 a longitudinal section through the joint.

The no 3 com )OSGd of two telescoain pipes a, (Z, of which lower pipe at, is provided with an upper conit'orm neck 7), received within pipe (Z, and having a top flange. 2'. Between tapering neck 7), and outer pipe (Z, is interposed a divided ring 0,

shown to be composed of four sections though the number of such sections may obviously be varied. Ring 0, has an inner wall tapered to correspond to the conicality of neck 7), while its cylindrical outer wall is adapted to frictionally engage the inner wall of pipe (Z. Within pipe 0, is centered a rod 0. having a tapering head j, that fits into the tapering neck Z2, and thus supports pipe at. The lower threaded end of rod 6, tapped into a nut f, having an upper groove with-in which the lower end of pipe (4-, is received. Nut f, is rotatably mounted upon a foot 9, that rests upon the floor of the mine.

In use, the pipe d, is raised until it engages the roof of the mlne, 111 which posltion it will be malntalned by the wedging b. Any increase of pressure on the prop will increase the wedging action of the ringsections, so that the joint will be correspondingly tightened. By turning nut f, the prop may be either slackened or distended whenever necessary.

I claim:

L A mine prop comprising an upper pipe, a teiescoped lower plpe havlng a conitorm neck within the upper pipe, and a sectional ring interposed between said neck and upper pipe.

2. A mine prop comprising an upper pipe, a telescoped lower pipe having a coniform neck within the upper pipe, a sectional ring interposed between said neck and upper pipe, and a rod inclosed by the lower pipe and having a tapering head that engages the neck.

3. A mine prop comprising an upper pipe, :1 telescoped lower pipe having a conit'orm neck within the upper pipe, a sectional ring interposed between said neck and upper pipe, a rod fitted within the lower pipe and having a threaded lower end, a nut engaging said end, and a foot rotatably supporting the nut.

Signed by me at Cologne, Germany this 11th day of June 1909.

EMANUEL soHArER. 

